Piston ring



Nov. 15, 1927.

c. .lol-msfrgaN E T AL PIsToN 1mm Filed Dec. 2l. '1925 INVENTRQ( w77@MmZO-RNE Y.

and -a simpley and reliable'mechanical con corner of said groove.

' y or receiving chamber, where it may again be tion of the cylinderwall and showing a ring variation in the elastic-membeireceiving l1,649,474 TES PATENT OFFICE.

Patented Nov. 15, 1927 UNITED STA ennuis r'. JOHNSTON AND GEORGE G.anus, on sAirrnANcIsco CALIFORNIA.:

.P IsToNnING. i'

.Applioaton filed December 21, 1925. Serial No. 76,'655. Y

The object of our invention is a iston ring groove and the rin-g and themanner in which employing special structural detai swhereby `leakage'between the piston and cylinder is the oil ports through'the pistonwall. avoidedm ost efficient lubrication is attained Vf Figs. 5, 6 and7illustrate forms of velastic 'members 1n perspective to-'expand the ringagainst the' cylinder and retain its contact struction secured wherebythe ,y y

with the lower face of the piston groove.

cost of production, efficiency inservice and long life of the ringpiston and cylinder isattained.

.Theseobjects are accomplishedby forming the= ring to receive a pressurewhich may be l"the ymannerin which the components for expansion and'contact vbet'v'veen', the piston resolved into two components, 'one ofthese groove and ring are retained byemploying components'being toexpand the ring'against our invention.` f 'Y I i `In Figs. 2, 3, 4

the pistonand cylinder walls and` between the ring Iand piston grooveare greatl 'eiraggeratedr for vthe purpose of 'more c early theinventive steps.`

the cylinder wall, and the othercomponent to 4retain the ring in contactwith one of the piston groove faces, and inl combination wit the saidring an elastic element which establishes 4.the .said pressuresubstantially about the inner potions of said ring, the saidelasticwelement being normally in comrefer toidentical parts. o y.pression between the piston groove and the A conventional cylinder `isindicatedfbythe ring, .and seating. substantially within the numeral 1,havingunlet and' outletpo'rts' at 2, 8 respectively'and' a tiring meansor spark showing,

1 There ,mayalso be formed in 'the ring vperiphery a. scraping groove inwhich a `resijirvoirof oilmay be retained with a sur- --plus fof scrapedoil passing backthrough4v the pistonv walls into a ,conventionalI oilsump -at 8., f The'piston is provided with packin frings 9, 10,-.inplace, and at llfa'groove or'receiving'an oiling or'scraping ring.

'I ln thebottom or back wall of for receiving our ring we prefer tointroduce a plurality ofports or passages 1 2, `and these it willbenoted, larefpositioned at for above v'the center of the grooveWh'ereby'a pocket is formed in which oil as at 13,'"is retained betweenthe' ring and the bottom of the piston groove. This insures a supply foran oil lm to be retained between the lower 16 cut from the inner upperedge diagonally yre-used-.. l, 4.

- .Where this feature of our inventionis employed wejprovide anopeningthrough the" piston wall from thepiston groove and posi- 4,tion theseabove the bottomof the groove so that thereis'an `oil trap or reservoirretained at all times between the inner ring wall and the back wall ofthe piston groove which trap or reservoir overflows through thesaidpis-l toni-partsfQ.'4

By referring to the accompanying drawingT-our invention will be madeclear.

ig. 1 illustrates a conventional cylinder `in section having a pistontherein shown in full view.

Fig. 2 is an enlarged fragmentary sectionA through `a portion of thepiston and a porform ofour invention.

and em lo ing one p y to Fig. 2 but showing a Fig. Sis similar two facesof the groove 16 ments of conical surfaces.

VAn elastic element 17 formed of a piece of spring wire bent sinuouslyis interposed between the corner 18 ofthe said groove 11 land the bottomof the recess 16,l and the sinuosities of the element 17 form a .plu-

su'rface of the ring and showing one form of oil scraping groove. l

Fig.. 4 is similar to Fig. 3 but .showing a Variation in scraping groovewhereby an o il reservoir is provided in the ring.

Figs. 2,' 3 and 4 illustrate a preferred form of oil trap 0r reservoirbetween the piston are in effect seg- Throughout the 'figures similarnumerals plug atfl, a piston at 5, and connectin'gfrodfff' the action ofthe towards the center of the ring so that the this is retained byappropriately positioning and 8, .the spaces between 1 thegroove. l

ring surface and the'lowerV faceof the groove i rality of springs orelastic members in compressionabout the periphery of the ring and thesesinuosities exert a pressure having a direction through the upper cornerofthegroove at 18 and substantially through the centerof the ringsection forcing the ring outward and against the cylinder wall 1, anddownwardagamst groove surface and the oil film at. 14.

The ring shown inI cross section at 19 of Fig. 3 is provided with achamfered face i. der wa'll 1 and a downward the cylinder `wall whichnow passes through a plurality of holes ,25 flowing into theoilreservoir 13 and retainingA an oil storage therein at all times, thesuperfluous oil passing oil' through the holes 12 and thence ythroughthe piston wall.'

The vring section shown at 26, 4 is vsimilar to that of 19, Fig. 3except that the scraping edge at 27 is provided by formi-ng an 'upwarddirected groove 28,. and oilports 29 and a solid expansion member 30.-This form has the advantage of providing a secondI oil trap orreservoir at 31 between the lower upward directed surface of the groove28 and the piston wall 1, so that oil which may be scraped from oneportion of the cylinder` surface 1 is first stored in a body at 3l adjacentand in contact with the cylinder wall ,r 1, thek superfluous oilpassing through the port 29 and retaining the primary oil resere voir at13 and the su erfluous oil passing through the piston wa ls by the ports12 as before. p

\ Three forms of elastic elementsare here shown, that lof Fig. 5 beingsimilar to that set forth in United States Letters Patent No. 1,411,360,issued on April 4, 1924, to Chas. F. Johnston, and adapted to use in ourinvention.

The element shown Iin Fig. 6 is a helicalV spring in which the.compression of the individual. coils provides the elastic feature whilethat shown in 30 is preferably of asbestos, hemp or other elastic andrelativel'ly solid material formed as a core, either by weaving, moldingor other conventional method. n

In the several forms of elastic elements and ring sections here shown,with or without the scraping edges 24 or 27 there isprovided the"primary oil yreservoir at 13 which, if no ports 25, or 29 are provided,issupplied either from oil :passing from the interior-'of e5 It willnonT be seen that upon the upstroke in the direction of the arrow 33 ofthe piston oil maybe gathered from the cylinder wall 1, whereas upon thedown stroke in the direction ofthe arrow 34, the said oil storage at 13may be supplied from the oils'plas'hing.

from the inside of the piston. In the latter case the splashed oil maywith advanta e collect upon the ledge 35 aslit descends t e-nf nersurface 36 of the piston 5, and thus and at all times be `furnishedthrough the 1,2, thus providing an 13 to retain yfthe film1`4. l It willbeunderstood that -various forms of ring surfaces may be employed,without departing from our invention which is particularly directed tothe sealing of the ring against the piston wall and against the lowersurface of the piston groove vby-'an elastic adequate supp yv at elementin compression seated in the u per` corner o r between the upperportions o the piston groove as at 18, Fig. 2 and as at 20, 23 of Fig. 3and this element exerts a -diagonal pressure as indicateddiagrammaticalvly bythe arrow 37 in Fig. 8 and which diagonal pressureis resolved into the two components 38 tending to expand the ring at alltimes against the piston wall, and 39 tending to at vall tignes retain aclosure' between the lower face of the ring and the piston groove andthe maintenance of an oil seallower portion of the piston ring andpiston groove.

'We claim: l Y l 1. In a hollow piston adapted'to reciprocatevertically, a groove adapted to receive a piston'ring, an inner oilcollecting ridge lou "ing and lubricating film at 14 between the formingan oil trap, ports opening from said trap throughy the piston wall andinto said groove and substantially above the lower face of sa-idlgroove.

2. In a hollow piston adapted to reciprocate vertically, a grooveadapted to receive a piston ring, an inner oil collecting ridge formingVan oil trap, portsv opening from said trap through the piston wall andinto said groove and substantially above the lower face of said groovein combination with a ring spaced from the inner groove surface andforming between the ring and said inner surface an oil reservoir.

' CHARLES F. JOHNSTON.

GEORGE G. BEES.

